Four-cylinder offset rotary machine



Sept. 10, 1935. F. WOLFF 8 FOUR-CYLINDER OFFSET ROTARY MACHINE Filed May25, 1934 2 Sheets-Sheet l x j w 5\\ 76 77 9 I8 I 4 o 8 3 5 75 "I ZrDMenZOf/ 23 721 l/aj/f Sept. 10, 1935. v F, WOLFF 2,014,218

FOUR-CYLINDER OFFSET ROTARY MACHINE Filed May 2 5, 1934 2 Sheets-Shget 2Patented Sept. 10, 1935 UNITED STATES FOUR-CYLINDER OFFSET ROTARYMACHINE Fritz Wolff, Plauen, Germany, assignor to Vomag-Betriebs-A.-G.,Planen i. V.

Application May 25, 1934, Serial No. 727,555 In Germany June 1'7, 1933Claims.

This invention relates to a cylinder starting and stopping device in afour cylinder rotary ofiset machine.

It is known to arrange the axes of the rub- 5 ber and plate cylinders infour cylinder rotary offset machines in a common plane and to remove thecylinders from each other in this plane in order to throw offimpression. The known adjusting devices suffer, however, from thedrawback that the contact of the grooves provided in the rubbercylinders for fixing the blankets causes vibrations which interfere withthe uniform transfer ofthe impression from the plate cylinders to therubber cylinders.

To eliminate this drawback and insure reliable arrangement of theimpression cylinders the invention provides that one of the two platecylinders remains stationary whereas the adjacent rubber cylinder isslightly removed there- -from during throwing ofi and the next rubbercylinder is moved twice this distance, and the other plate cylinder,with the respective inking apparatus and damping device, is disposed ina movable frame and displaced by the latter to such an extent that asufficient space is provided betweenthe plate cylinder and its rubbercylinder. To insure satisfactory transfer of the impression to the paperin spite of the adjustability of this plate cylinder and reliably takeup the resulting counter pressure of the plate cylinder and transmit itto the machine frame, it is advisable to support the bearing carriage ofthe adjustable plate cylinder by means of a wedge in the direction ofdisplacement during printing 35 relative to a stationary machine walland thus transmit the abutment forces in straight direction to themachine frame.

On the accompanying drawings one form of the invention is illustrated inFigure l in vertical 4 section and Figure 2, which is a diagrammaticside view, shows the device for lifting the inking rollers.

Referring to the drawings, the paper web I tobe printed is fed betweenthe two rubber cylinders 2 and 3 in known manner and printed on frontand back. The rubber cylinders 2 and 3 cooperate, respectively, withplate cylinders 3 and 5 provided with the usual inking apparatus anddamping means. The axes of the cylinders 2, 3, 4, 5 are arranged in acommon plane, in which the lines of contact of every two adjacentcylinders will thus be disposed also during the printing process.

55 The plate cylinder 5 with its appurtenant inking apparatus 6 isstatio-narily positioned in the machine frame.

The two rubber cylinders 2 and 3 are supported by two eccentric bushes39 possessing, respectively, the toothed rim segments '1 and 8 which 6engage a common toothed wheel 9 and are turned by the latter alwaysthrough equal angles. How- ,ever, the eccentricity of the bushes ischosen so that at a certain angular turn of the wheel 9 and acorresponding displacement of the two 10 bushes the rubber cylinder 3will be moved away from the stationary plate cylinder 5 to the extent ofabout 2 mm. and the rubber cylinder 2 about 4 mm. with the result thatwhen the impression is thrown off a space of 2 mm. will remain be- 15tween the plate cylinder 5 and the adjacent rubber cylinder 3 and alsobetween the two rubber cylinders 2 and 3.

The plate cylinder l with its inking apparatus iii and clamping deviceI! is positioned in 20 a carriage I2 which is displaceably supported bythe rolls l3 on an edge of the machine frame l4. Each side of thecarriage i2 is fitted with a roll IS, the rolls being rotatably disposedand engaging cam discs l6 movably disposed on the 25 machine frame It bymeans of the shaft ll. The shaft I? carries also an adjusting lever l8connected with an intermediate lever 26 by the rod [9. The intermediatelever 20 is secured to the shaft 2| passing transversely through the ma-30 chine frame l4 and carrying a lever 22 which, together with theconnecting rod 23 and the throwoff lever 24, serves for turning theshaft 21 when the machine is to be started or stopped. The shaft 2 I, bymeans of the lever 25, the coupling bar 26 and the auxiliary lever 27,turns also the wheel 9 by means of which the rubber cylinders 2 and 3can be thrown on and off in the manner described. The cam discs it areshaped so that on their rotation the carriage I2 is sufficientlydisplaced to provide suflicient space during throwing-off between theplate cylinder 4 and the laterally displaced adjacent rubber cylinder 2.

During the displacement of the plate cylinder 4 the respective inkingrollers of the inking apparatus it can be lifted off from the cylinderin known manner by a mechanical device moved preferably from the shaft Mas shown in Figure 2.

To transmit in printing position the counterpressure exerted by theplate cylinder 4 in a reliable manner to the machine frame withoutexposing the carriage l2 to the danger of tilting rearwardly, the rearedge of the carriage I2 is provided with an abutment 28 whereas thevertical column 29 of the frame l 4 carries a supporting surface 38.Between the parts 23 and 3! a wedge 3|. is provided which can be raisedand lowered by means of the link 32, the double-armed lever 34 rotatableon the bolts 33, the coupling bar 35 and the lever 36 positioned on theshaft l'l. During displacement of the carriage l2 when the impression isthrown off the wedge 3'! is first slightly lifted before the carriage,under the action of the cam disc l6, begins its lateral motion, whereaswhen the cylinders are brought into printing position first thecylinders 2, 3, 4 are placed in working position and then the wedge 3ilocks the carriage i2 in printing position. The Wedge M can be placed solow as to be approximately on a level with the axis of the cylinder 4.

It is not absolutely necessary to dispose the carriage l2 displaceablyon the machine frame M,

since it would be possible to support all the parts to be carried by itin a frame which could be movable about a shaft disposed on the soleplate of the machine frame.

To prevent the carriage l 2 from rising in printing position and thuscause a displacement of the cylinder 4 in vertical direction relative tothe rubber cylinder 2, a ledge 37 is provided on the carriage whichengages a projection 38 of the :machine frame M when in printingposition.

I claim:

1. In a four cylinder oifset rotary machine, in which the axes of tworubber and two cooperating plate cylinders are disposed in a commonplane and movable relative to one another for throwing off impression,inking and damping means for the plate cylinders, one of the platecylinders being stationarily disposed in the machine frame, eccentricbushes for supporting the rubber cylinders, toothed rim segments formingpart of said bushes, a toothed wheel in mesh with said segments, drivingmeans for said wheel, a carriage carrying the other plate cylinder anddisplaceably supported by the machine frame, and means connected withsaid driving means for said toothed wheel for displacing said carriageduring stop-impression and removing the rubber cylinders from oneanother and from the stationary plate cylinder to a predetermineddegree.

2. In a machine according to claim 1 a wedge for supporting the carriagein the direction of displacement during printing relative to astationary machine wall.

3. In a machine according to claim 1 a ledge arranged on the side of thecarriage facing the inking means and a projection on the adjacent edgeof the machine frame, said ledge engaging said projection duringprinting to prevent rising of the carriage.

4. In a four cylinder offset rotary machine, in which the axes of tworubber and two cooperating plate cylinders are disposed in a commonplane and movable relative to one another for throwing off impression,inking and damping means for the plate cylinders, one of the platecylinders being stationarily disposed in the machine frame, means forsupporting said rubber cylinders having toothed rim segments, a toothedwheel in mesh with said segments, driving means for said wheel,

a carriage carrying the other plate cylinder and displaceably supportedby the machine frame, and

means connected with said driving means for said toothed wheel fordisplacing said carriage during stop-impression and removing the rubbercylinders from one another and from the stationary plate cylinder to apredetermined degree.

5. In a four cylinder offset rotary machine, in 5 which the axes of tworubber and two cooperating plate cylinders are disposed in a commonplane and movable relative to one another for throwing off impression,inking and damping means for the plate cylinders, one of the platecylinders being stationarily disposed in the machine frame, means forsupporting said rubber cylinders, driving means for driving said rubbercylinders, a carriage for carrying the other plate cylinder anddisplaceably supported by the ma- 40 chine frame, and means connectedwith said driving means for the rubber cylinders for displacing saidcarriage during stop-impression and removing the rubber cylinders fromone another and from the stationary plate cylinders to a predetermineddegree.

FRITZ WOLFF.

